TY - JOUR
T1 - Critical Loading Characterization for MTDC Converters Using Trajectory Sensitivity Analysis
AU - Moawwad, Ahmed
AU - El-Saadany, Ehab F.
AU - El Moursi, Mohamed Shawky
AU - Albadi, Mohammed
N1 - Publisher Copyright:
© 1986-2012 IEEE.
PY - 2018/8
Y1 - 2018/8
N2 - This paper introduces a new technique to characterize the ac grids stability connected to multiterminal high-voltage direct current networks. The proposed method identifies the maximum active powers that converters can exchange with an ac network without losing the transient stability using trajectory sensitivity analysis. Therefore, the generators' rotor angles variations due to various converters active powers exchange are measured and normalized. Consequently, the norm of each trajectory vector is used as an indicator of the system proximity to instability. To enhance the accuracy of the method for online stability assessment applications, the steady-state initial conditions of the sensitivity network variables are precisely obtained using the Newton shooting method. For this purpose, the detailed differential and algebraic models representing the dynamics of the ac and dc networks have been formulated and analytically solved simultaneously with the sensitivity network. Comprehensive simulation studies on the IEEE 68-bus benchmark system are carried out using PSCAD/EMTDC for validation purposes. Results show that the modified approach provides more accurate results compared to the normal trajectory sensitivity analysis with less time compared to multiple time-domain simulations.
AB - This paper introduces a new technique to characterize the ac grids stability connected to multiterminal high-voltage direct current networks. The proposed method identifies the maximum active powers that converters can exchange with an ac network without losing the transient stability using trajectory sensitivity analysis. Therefore, the generators' rotor angles variations due to various converters active powers exchange are measured and normalized. Consequently, the norm of each trajectory vector is used as an indicator of the system proximity to instability. To enhance the accuracy of the method for online stability assessment applications, the steady-state initial conditions of the sensitivity network variables are precisely obtained using the Newton shooting method. For this purpose, the detailed differential and algebraic models representing the dynamics of the ac and dc networks have been formulated and analytically solved simultaneously with the sensitivity network. Comprehensive simulation studies on the IEEE 68-bus benchmark system are carried out using PSCAD/EMTDC for validation purposes. Results show that the modified approach provides more accurate results compared to the normal trajectory sensitivity analysis with less time compared to multiple time-domain simulations.
KW - AC-DC power flow
KW - MTDC networks
KW - deferential algebraic equations (DAE)
KW - time-domain simulation
KW - trajectory sensitivities
KW - transient stability
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U2 - 10.1109/TPWRD.2018.2809565
DO - 10.1109/TPWRD.2018.2809565
M3 - Article
AN - SCOPUS:85042875288
SN - 0885-8977
VL - 33
SP - 1962
EP - 1972
JO - IEEE Transactions on Power Delivery
JF - IEEE Transactions on Power Delivery
IS - 4
ER -